On Monday, January 02, 2012 11:35:31 pm Vijay Singh wrote: > I have see the following call sequence in profiles: > > > called/total parents > index %time self descendents called+self name index > called/total children > > 0.02 1.14 3822699/7559737 tcp_do_segment > [154] 0.5 0.03 2.26 7559737 callout_reset_on > 2.19 0.02 7573352/94883048 spinlock_exit > 0.01 0.04 7573352/11975031 callout_lock > > It is my perception that spinlocks are expensive. Since general TCP > locks are sleep mutexes, would there be any merit in building a TCP > callout facility using sleep mutexes? I can hack something up and > share here but wanted to check if people know of an existing facility > that might be used here?
The spinlock in question is probably the callout_mtx itself. The problem is that you have to be able to acquire some sort of lock in the timer interrupt to check the timer state to see if a timer thread should be scheduled. That has to be a spin lock. -- John Baldwin _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
